tidy3d.FieldProjector

class FieldProjector

Bases: Tidy3dBaseModel

Projection of near fields to points on a given observation grid.

Parameters:

• attrs (dict = {}) – Dictionary storing arbitrary metadata for a Tidy3D object. This dictionary can be freely used by the user for storing data without affecting the operation of Tidy3D as it is not used internally. Note that, unlike regular Tidy3D fields, attrs are mutable. For example, the following is allowed for setting an attr obj.attrs['foo'] = bar. Also note that Tidy3D` will raise a TypeError if attrs contain objects that can not be serialized. One can check if attrs are serializable by calling obj.json().

• sim_data (SimulationData) – Container for simulation data containing the near field monitors.

• surfaces (Tuple[FieldProjectionSurface, ...]) – Tuple of each FieldProjectionSurface to use as source of near field.

• pts_per_wavelength (Optional[int] = 10) – Number of points per wavelength in the background medium with which to discretize the surface monitors for the projection. If None, fields will will not resampled, but will still be colocated.

• origin (Optional[Tuple[float, float, float]] = None) – [units = um]. Local origin used for defining observation points. If None, uses the average of the centers of all surface monitors.

• this (.. TODO make images to illustrate)

See also

:class:`FieldProjectionAngleMonitor

Monitor that samples electromagnetic near fields in the frequency domain and projects them at given observation angles.`

Notebooks:

• Performing near field to far field projections

Attributes

currents	Sets the surface currents.
frequencies	Return the list of frequencies associated with the field monitors.
is_2d_simulation
medium	Medium into which fields are to be projected.
attrs

Methods

apply_window_to_currents(proj_monitor, currents)	Apply windowing function to the surface currents.
compute_surface_currents(sim_data, surface, ...)	Returns resampled surface current densities associated with the surface monitor.
from_near_field_monitors(sim_data, ...[, ...])	Constructs FieldProjection from a list of surface monitors and their directions.
project_fields(proj_monitor)	Compute projected fields.
set_origin(val, values)	Sets .origin as the average of centers of all surface monitors if not provided.
trapezoid(ary, pts[, axes])	Trapezoidal integration in n dimensions.

Inherited Common Usage

sim_data

surfaces

pts_per_wavelength

origin

property is_2d_simulation

classmethod set_origin(val, values)

Sets .origin as the average of centers of all surface monitors if not provided.

property medium

Medium into which fields are to be projected.

property frequencies

Return the list of frequencies associated with the field monitors.

classmethod from_near_field_monitors(sim_data, near_monitors, normal_dirs, pts_per_wavelength=10, origin=None)

Constructs FieldProjection from a list of surface monitors and their directions.

Parameters:

• sim_data (SimulationData) – Container for simulation data containing the near field monitors.

• near_monitors (List[FieldMonitor]) – Tuple of FieldMonitor objects on which near fields will be sampled.

• normal_dirs (List[Direction]) – Tuple containing the Direction of the normal to each surface monitor w.r.t. to the positive x, y or z unit vectors. Must have the same length as monitors.

• pts_per_wavelength (int = 10) – Number of points per wavelength with which to discretize the surface monitors for the projection. If None, fields will not be resampled.

• origin (Coordinate) – Local origin used for defining observation points. If None, uses the average of the centers of all surface monitors.

property currents

Sets the surface currents.

static compute_surface_currents(sim_data, surface, medium, pts_per_wavelength=10)

Returns resampled surface current densities associated with the surface monitor.

Parameters:

• sim_data (SimulationData) – Container for simulation data containing the near field monitors.

• surface (FieldProjectionSurface) – FieldProjectionSurface to use as source of near field.

• medium (MediumType) – Background medium through which to project fields.

• pts_per_wavelength (int = 10) – Number of points per wavelength with which to discretize the surface monitors for the projection. If None, fields will not be resampled, but will still be colocated.

Returns:

Colocated surface current densities for the given surface.

Return type:

xarray.Dataset

static trapezoid(ary, pts, axes=0)

Trapezoidal integration in n dimensions.

Parameters:

• ary (np.ndarray) – Array to integrate.

• pts (Iterable[np.ndarray]) – Iterable of points for each dimension.

• axes (Union[Iterable[int], int]) – Iterable of axes along which to integrate. If not an iterable, assume 1D integration.

Returns:

Integrated array.

Return type:

np.ndarray

static apply_window_to_currents(proj_monitor, currents)

Apply windowing function to the surface currents.

project_fields(proj_monitor)

Compute projected fields.

Parameters:

proj_monitor (AbstractFieldProjectionMonitor) – Instance of AbstractFieldProjectionMonitor defining the projection observation grid.

Returns:

Data structure with Er, Etheta, Ephi, Hr, Htheta, Hphi.

Return type:

AbstractFieldProjectionData

__hash__()

Hash method.